Hello Forum,
I have joined a few Breps together and inserted them in a list of closed Breps. After that everything looks fine since the Panel shows me a list of Closed Breps.
However when in the next step I try to project the Breps, they don’t show up and a panel connected to project shows me the joined Breps as invalid.
Any idea how this can be fixed?
arc projection.3dm (96.1 KB)
arc projection.gh (15.5 KB)
I would loft pairs of curves.
lofted_pairs.gh (16.0 KB)
PS: the input curves are internalised. The Rhino file isn’t needed.
2 Likes
It doesn’t really make sense to project 3D breps onto a plane. You could do this, but it’s not right.
When you join breps together as you’ve done here, Brep Join is the correct tool, not Solid Union.
arc projection_2024Aug26a.gh (15.7 KB)
2 Likes
Yes, lofting pairs is a much better approach! It’s interesting to see your use of the Fit Curve. This seems to be a handy component. After I saw it, I remembered the curvature continuity G0-G3 stuff I read some time ago. I should have paid more attention to the smoothness of my input curves. Thanks for your instructive post!
Okay, I see. Brep Join is obviously the correct component. I already thought that Solid Union was not quite right, but it seemed to work, so I went with it.
Why does it not make sense to project 3D Breps onto a plane? I don’t have much understanding of what a Brep is. Does this have something to do with the nature of 3D Breps? Does it make more sense to project “some other 3D stuff”?
I have noticed that the Brep projection doesn’t look quite right when I zoom in. What’s going on there?
It makes sense to project points and curves to a plane, not breps,
You have Loft options set to ‘Straight’, and as I said, projecting breps to a plane is incorrect, You can create a cross-section like this (purple group):
arc projection_2024Aug27a.gh (10.6 KB)
2 Likes
Ok, it’s incorrect, but I didn’t understand the why. I have asked this ChatGPT and it said something like “breps are a “complex data” structure not suited for projection” Instead I should go with a mesh or contours.
After a search I found this post that told me I should use Mesh Shadow. This almost produces the result I desire. The issue is that Mesh Shadow shows an error and some “bricks” are missing.
lofted_pairs (1).gh (9.3 KB)
I did; unfortunately, it didn’t provide me with a good answer. Therefore, I have to annoy you humans again. Sorry! If someone could me a hint about what is going wrong, I’d appreciate it. Thank you in advance, lovely humans!
1 Like